In the past, in connection with a high temperature combustion chamber such as one used in a process of synthesis gas generation, measurement of the internal temperature within the chamber has been carried out using thermocouples inserted through the side of the vessel. However, because of the severe operating conditions encountered, the thermocouples have been subject to failure and a better way of measuring the internal temperature has been needed.
Some previous attempts to make use of an optical system, limited the view to the bottom hole in the chamber that led to the relatively cold quench area of the high temperature combustion chamber. Also in the past there have been arrangements for making a sighting into the interior of a high temperature combustion chamber so as to measure the radiation therein. But, such arrangements have required extensively well protected sight holes and even with the expensive equipment thus required there has been problems with the interior conditions that are being measured so that the results have not been satisfactory.
There is a U.S. Pat. No. 3,529,121 to S. N. Bobo et al, Sept. 15, 1970 which employs an optical fiber as a radiation conduit. It is incorporated in a welding rod. However, the operation of that arrangement includes the melting of the end of the optical fiber which is in contact with the weld. Therefore it is the melted temperature of the optical fiber itself which is being measured. Clearly, that would not be satisfactory for a high temperature combustion chamber measurement such as is involved in the subject application. Among other reasons, the optical fiber would soon be melted away and no longer effective.
Thus, it is an object of this invention to provide a radiant energy conduit that is associated with the burner of a high temperature combustion chamber in such manner that it may make a measurement of the interior temperature of the chamber without any harm to the optical radiant energy conduit.